[jeepwayoflife]

Biggest problem with speed in 4wd is turning. If you had to turn a sharp curve at high speeds and the wheel had no way to slip it could damage the axle in some way. You should never have it in 4wd hi or low unless you are in a place where one wheel could slip during turns. Driving in a straight line is no problem.

Idk about jk gearing, but on TJ's the front and rear gearing is .01 different... Dont ask me why but they are 4.10 and 4.11 ect. I would assume JK's are the same? This means that even in a straight line you can get some sort of driveline bind. Something to think about

 

[jeepwayoflife]

The minor difference is because the tooth counts on the gears aren't exactly the same.

A 4.09 gear has 45 ring gear teeth and 11 pinion teeth. (45/11 = 4.090909)
A 4.10 gear has 41 ring gear teeth and 10 pinion teeth. (41/10 = 4.100000)
A 4.11 gear has 37 ring gear teeth and 9 pinion teeth. (37/9 = 4.111111)

These different gear rations are considered functionally equivalent. You can run them all in whatever combination works in your axles without fear of binding. The D30 has a 4.11 gear set. The D44 has both the 4.10 and 4.09 gear sets. Given that a 0.02 difference between 4.09 and 4.11 is only 1/2 of a percentage point difference, you won't bind if you run the two in the same vehicle. There is enough slop in the drivetrain to deal with this without any problem. The fact is, you can get more of a difference just by over inflating the front tires and under inflating the rear tires.

Now, if you try to run 4.56 gears and 4.11 gears, that's a major difference. Like a 10% difference. That will cause binding if you try to run those with the same size tires. Though if you get staggered tires to match the ratios (i.e. 10% larger tires with the 4.56 than the tires running the 4.11s) you can get away with it.

Very interesting. Thanks for the info! The only thing wrong I have heard from Jerry, but maybe I just misunderstood what he said